The Hawaiian Islands are both the extinction and invasive species capitals of the world. The result has been Hawaiian ecosystems fundamentally changed in form; that is, ecosystems replete with a mix of novel and native species. Most native Hawaiian plant species are bird-dispersed, yet no native avian dispersers remain in most Hawaiian ecosystems. Thus, ecosystem functioning will only be maintaine
d by the handful of invasive vertebrate dispersers that now reside on the islands, most of which are birds. The Hawaii VINE Project seeks to determine how well different species of non-native birds disperse native plant species across environments, whether non-native rat species have a cumulative positive (via seed dispersal) or negative (via predation on bird seed-dispersers and/or via seed predation) impact on plant communities, and creating predictive models to be used to improve non-native plant management plans, while facilitating the recovery of native threatened, endangered, and at-risk plants. Using multiple sites across the island of Oahu, the Hawaii VINE Project examines [1] how the structure and dynamics of seed dispersal networks vary across ecological contexts, [2] how seed dispersal competence of non-native species varies across ecological contexts to influence ecosystem functioning, and [3] how ecosystem functioning is maintained across new spatial and temporal extents. The project relies on extensive field-based data collection (collected year-round for four years), including diet sampling, behavioral observations of birds and rats, small mammal and bird censusing, and field experiments. We apply ecological modeling techniques such as hierarchical occupancy modeling and movement ecology models to describe and quantify seed dispersal effectiveness in novel Hawaiian communities. The Hawaii VINE Project is funded by the SERDP (a joint DOD, DOE, and EPA program).
